Brooks Glycerin 22 vs 23: What Changed, and Is the 23 Better?
The earlier Brooks figures describe a drop change from 10 to 8 mm; the cited RunRepeat samples measured 10.3 and 8.2 mm. The Glycerin 23 sample toe box was 4.1 mm taller, with very similar width readings. These are attributed construction differences, not individual fit or treatment results.
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The figures can help identify what to compare in an actual fitting. They do not establish the 23 as a hammertoe, orthotic or heel-pain winner, or prescribe the 22 for Achilles or calf symptoms. Check the actual model, size and device rather than buying by diagnosis alone.
Evidence status: This is a published-source specification comparison attributed to Tom Biernacki, DPM, FACFAS. No original product photos, measurements, wear-test notes or clinician-review records are available for these shoes. The brand and review-site figures are dated source reports; the laboratory figures are RunRepeat’s samples, not measurements performed by Podiatrist Tested. They do not establish comparative treatment outcomes, validated scores or a Seal award.
What Brooks says changed
The earlier sources describe Brooks’ DNA Tuned foam in both models, following its use in the Glycerin Max. The recorded stated drop changed from 10 to 8 mm, with Brooks describing 2 mm more forefoot cushioning. Earlier list prices were $165 and $175, a $10 difference, and listed weight rose slightly. These are dated manufacturer/launch reports, not a new price or availability check.
| Specification | Glycerin 22 | Glycerin 23 |
|---|---|---|
| List price | $165 | $175 |
| Stated heel-to-toe drop | 10 mm | 8 mm |
| Listed weight, men’s US 9 | 10.2 oz (289 g) | 10.6 oz (300 g) |
| Midsole | DNA Tuned | DNA Tuned |
| On sale on 28 September 2026? | No longer at Brooks US or Running Warehouse | Yes, at Brooks and running shops |
Sources: Brooks’ Glycerin 23 page, recorded September 2026; Glycerin 22 launch figures and both weights, for a men’s US 9, from Doctors of Running. No stack figures were recorded from the checked brand sources; the earlier retailers’ figures differed by a millimetre. The laboratory values below use their stated source, sample and method.
What the lab measured
The cited RunRepeat sample drop fell by 2.1 mm, compared with the brand’s stated 2 mm change. Sample forefoot stack differed by 0.8 mm and heel stack by 1.3 mm. Toe-box width readings were very similar, while height differed. A source discrepancy does not by itself prove a brand error: sample size, size/version and method matter.
| Measurement | Glycerin 22 | Glycerin 23 | Change |
|---|---|---|---|
| Toe-box width at the big toe | 73.7 mm | 73.9 mm | The same |
| Width at the widest point | 96.3 mm | 96.1 mm | The same |
| Toe-box height | 23.6 mm | 27.7 mm | 4.1 mm taller |
| Heel stack | 38.5 mm | 37.2 mm | 1.3 mm lower |
| Forefoot stack | 28.2 mm | 29.0 mm | 0.8 mm higher |
| Measured drop | 10.3 mm | 8.2 mm | 2.1 mm lower |
| Weight | 293 g | 303 g | 10 g heavier |
| Midsole hardness (Asker C, higher is firmer) | 30.0 AC | 29.2 AC | Much the same |
| Energy return at the heel | 54.8% | 54.1% | The same |
| Heel shock absorption | 133 SA | 140 SA | About 5% higher SA reading |
| Force to bend the forefoot | 15.0 N | 15.2 N | Much the same |
| Heel counter stiffness (1 to 5) | 3 | 4 | Stiffer |
| Insole thickness | 5.0 mm | 4.4 mm | 0.6 mm thinner |
| Force to twist (torsional rigidity) | 4 of 5, older test | 14.0 Nm | Not comparable |
Source: RunRepeat lab, one pair of each, read 28 September 2026, with the same toe-box, cushioning and bending tests on both shoes. Hardness is on the Asker C scale and shock absorption in RunRepeat’s SA units; the lab now measures torsional rigidity in newton-metres and tested the older shoe on a 1-to-5 scale, so the two cannot be compared (the median of the 24 shoes we review with the newer test is 14.5 Nm). Medians of the lab-measured shoes we review (34 for the toe-box figures, 35 for the rest): 72.8 mm at the big toe, 95.2 mm at the widest point, 27.0 mm of toe-box height, 38.7 mm of heel stack, 8.5 mm of drop, 137 SA and 15.3 N. These are the earlier attributed sample data and comparison-set counts, not a current inventory or an independent retest. Differences between samples do not by themselves establish effects on pain, injury, balance, Achilles loading or device fit.
What these specifications can support
Toe-box dimensions: The cited 23 sample measured 27.7 mm tall versus 23.6 mm, a 4.1 mm difference; the 22 was lower than all but three in the earlier 34-sample set. The 23’s big-toe and widest-point readings were 73.9 and 96.1 mm, above that set’s medians and very similar to the 22. These figures do not establish clearance for every size, hammertoe, nail or device. Check rubbing and depth in the actual pair; our toe-box chart gives the attributed measurements.
Drop: The earlier stated figures are 10 and 8 mm; the cited samples measured 10.3 and 8.2 mm. These differences do not establish preferred models for neuroma, metatarsalgia, Achilles or calf symptoms, or measure how much load changes in a particular wearer. The drop chart compares geometry and evidence limits, not a validated therapeutic range.
Hardness, absorption and stiffness: The cited hardness readings were about 29 to 30 Asker C, among the five lowest of the earlier 33-sample set. The 23’s heel SA reading was about 5% higher and 12th of 35; heel-counter scores were 4 and 3 on the stated scale. At 303 g the 23 sample was 10 g heavier. These are different laboratory measures, not proof of heel-pain relief, perceived softness or pronation control.
Should you switch?
Compare the Glycerin 23 when…
- You want to try a sample toe box 4.1 mm taller. Rubbing or a hammertoe does not prove this model fits; verify clearance in the actual pair.
- You need to fit a prescribed device. The sample toe-box and liner measurements do not establish usable internal volume or an automatic orthotic winner.
- You want to compare the roughly 5% higher sample SA reading and different heel-counter score. Neither is a clinical pain-relief ranking.
- You want to compare the lower sample drop. Forefoot symptoms do not establish that this change helps or makes the 23 the preferred model.
Compare a Glycerin 22 listing when…
- You want to compare the 10.3 mm sample drop with 8.2 mm. A tendon or calf symptom does not prescribe the 22.
- An existing pair suits you and you want to compare another listing. The sample width readings are very similar; current model, size and condition still need checking.
- You want to compare the 10 g lower sample weight. This is a construction difference, not an original PT comfort or gait result.
Orthotics and inserts
The earlier sources describe removable insoles, with sample thicknesses of 4.4 and 5.0 mm. That 0.6 mm difference and a 4.1 mm taller sample toe box do not measure remaining interior volume, device shape or secure fit. No quantitative liner-removed clearance comparison is documented here. Try the exact prescribed device in the actual shoe; our device-fit guide describes fitting questions, not completed clearance ratings.
Questions runners ask
Is the Brooks Glycerin 23 better than the Glycerin 22?
The cited samples differ in toe-box height, drop, heel shock absorption and weight. These figures do not establish better outcomes for most feet or heel, Achilles and calf symptoms. Compare actual fit and activity needs; no original PT wear or treatment comparison is available.
What changed from the Glycerin 22 to the Glycerin 23?
The earlier Brooks/launch figures give 10 to 8 mm of stated drop, $165 to $175 and DNA Tuned foam. The cited samples differed by 2.1 mm of drop, 4.1 mm of toe-box height, about 5% in heel SA reading and 10 g in weight. Those are source-specific construction observations, not clinical outcomes.
Is the Glycerin 23 wider than the Glycerin 22?
The cited samples were within 0.2 mm at the big toe and widest point; the 23 measured 73.9 and 96.1 mm, above the earlier dataset medians. Its toe box was taller. Earlier Brooks sources listed Medium (D), Wide (2E) and Extra Wide (4E) for men; the samples do not test every width/size or establish individual fit.
Does the Glycerin 23 have a lower drop?
The dated stated figures are 8 mm for the 23 and 10 mm for the 22; the cited samples measured 8.2 and 10.3 mm. A lower geometric reading does not by itself establish symptom relief or a preferred model.
Is the Glycerin 22 discontinued?
The earlier page recorded replacement by the 23 and absence from Brooks US and Running Warehouse on 28 September 2026. That is a dated availability report, not a fresh check of every size, retailer or market. Verify the exact current listing before purchase.
Is the Glycerin 23 good for plantar fasciitis?
The cited sample was 12th of the earlier 35-shoe set for heel shock absorption, with a recorded heel-counter stiffness score. These are construction observations, not a plantar-fasciitis treatment trial or a pronation-based model prescription. Heel pain has several possible causes. Our running-shoe guide compares related published options and evidence limits.
Read the full analysis
Our spec analysis of the Brooks Glycerin 23 carries its full figures and sources, and our Ghost 17 vs Ghost 18 comparison does the same for Brooks’ other neutral trainer. For the brand as a whole, see Brooks and HOKA vs Brooks.
Sources
- Brooks, Glycerin 23 men’s product page (price $175, DNA Tuned, “2mm more” forefoot cushioning, Medium, Wide and Extra Wide), and the Glycerin collection page, which no longer lists the 22, read September 2026.
- Doctors of Running, Brooks Glycerin 22 review (launch price $164.95, 10 mm drop, 10.2 oz / 289 g in men’s US 9; DNA Tuned first used in the Glycerin Max) and Glycerin 23 review (8 mm, 10.6 oz / 300 g), read September 2026.
- Availability: Brooks US and Running Warehouse, checked 28 September 2026.
- RunRepeat, Brooks Glycerin 22 and Brooks Glycerin 23 lab reviews, read 28 September 2026.
Correction (9 October 2026): Qualified unsupported treatment-winner, load, stability and orthotic-clearance inferences while retaining the attributed manufacturer and outside-lab figures. Source dates and earlier availability reports remain historical; no new product test or clinician-review sign-off is claimed. ACFAS heel-pain guidance provides clinical context, not evidence that either compared model is a treatment winner.
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